April 17, 2018

The story goes like…

Background

  • Between-group riots can increase in response to drought (Almer, Laurent-Lucchetti, and Oechslin 2017).
  • Some models show scarcity can reduce conflict (Butler and Gates 2012).

Model: Scarcity reduces conflict

From Butler and Gates (2012):

\[I_i = \frac{F_i + \eta}{\sum \limits_{i = 1}^N \left( F_i + \eta \right)} \left[\sum \limits_{i = 1}^N \left( R_i - F_i \right) \right]\]

  • \(I_i\): income for group \(i\).
  • \(F_i\): effort dedicated to conflict/protection of resource.
  • \(R_i\): resource available to group \(i\).
  • \(\eta\): state-provided property protection.

Data: Social Conflict Analysis Database (SCAD)

Geocoded records of conflict (Salehyan et al. 2012).

Data: Standardized Precipitation Evapotranspiration (SPEI)

A 0.5 degree spatio-temporal grid of data from 1990-2015 (Vicente-Serrano, Beguería, and López-Moreno 2010).

Prio-Grid

Population and travel time to urban area (Tollefsen, Strand, and Buhaug 2012).

Cropland

Fraction of land as cropland and pasture (Ramankutty et al. 2008).

Property Rights

  • “Rights to Resources”, 11 questions about the legal framework in each country in Africa (World Resources Institute 2014).
  • Water rights for many countries globally, but missing many countries in Africa (Alden Wily et al. 2017).

Data Summary

Variable Mean Std. Dev. Min. Max.
Days with riots 0.01301 0.58386 0 187
Riot occurred 0.00072 0.0268 0 1
Riot onset 0.00069 0.02626 0 1
Number of riots 0.00079 0.03213 0 13
SPEI -0.10487 0.98712 -8.01478 7.45265
Cropland 0.08097 0.14526 0 1
Population 83641.73736 214877.62255 0 8339141

Empirical Model

\[\begin{aligned} y_{it} = & \alpha + \beta \; \mbox{SPEI}_{it} + \beta_w \; (\mbox{SPEI} \times W_c) + \beta_m \; (\mbox{SPEI} \times M_c) + \\ & \gamma_{i} + \delta_{t} + \rho_{rm} + \phi_{cy} + \varepsilon_{it} \end{aligned}\]

  • \(\mbox{SPEI}\): drought deviation from long-run trend.
  • \(W_c\): Whether a country has laws providing for water rights.
  • \(M_c\): Whether a country has laws providing for mineral rights.

Results

Cross-sectional analysis of drought and resource property rights.
Dependent variable:
Conflict Onset
(1) (2)
Drought -0.00004 -0.0001
(0.0002) (0.0002)
Drought Mean Response 0.851*** 0.856***
(0.023) (0.023)
Drought X Priv Water 0.0001
(0.0005)
Drought X Priv Minerals 0.0005
(0.001)
Constant 0.001 0.001
(0.002) (0.002)
Observations 43,278 42,006
R2 0.042 0.042
Adjusted R2 0.040 0.040
Residual Std. Error 0.033 (df = 43178) 0.033 (df = 41906)
F Statistic 19.036*** (df = 99; 43178) 18.665*** (df = 99; 41906)
Note: p<0.1; p<0.05; p<0.01
‘Priv’ is whether the law provides for private resource rights. ‘Trad’
is whether the law provides for traditional or cultural resource rights.

References

Alden Wily, Liz, Fabrice Dubertret, Peter Veit, Katie Reytar, and Nicholas Tagliarino. 2017. “Water Rights on Community Lands: Landmark’s Findings from 100 Countries.” Land 6 (4). MDPI AG:77. https://doi.org/10.3390/land6040077.

Almer, Christian, Jérémy Laurent-Lucchetti, and Manuel Oechslin. 2017. “Water Scarcity and Rioting: Disaggregated Evidence from Sub-Saharan Africa.” Journal of Environmental Economics and Management 86. Elsevier BV:193–209. https://doi.org/10.1016/j.jeem.2017.06.002.

Butler, Christopher K, and Scott Gates. 2012. “African Range Wars: Climate, Conflict, and Property Rights.” Journal of Peace Research 49 (1). SAGE Publications:23–34. https://doi.org/10.1177/0022343311426166.

Ramankutty, Navin, Amato T. Evan, Chad Monfreda, and Jonathan A. Foley. 2008. “Farming the Planet: 1. Geographic Distribution of Global Agricultural Lands in the Year 2000.” Global Biogeochemical Cycles 22 (1). American Geophysical Union (AGU):n/a–n/a. https://doi.org/10.1029/2007gb002952.

Salehyan, Idean, Cullen S. Hendrix, Jesse Hamner, Christina Case, Christopher Linebarger, Emily Stull, and Jennifer Williams. 2012. “Social Conflict in Africa: A New Database.” International Interactions 38 (4). Informa UK Limited:503–11. https://doi.org/10.1080/03050629.2012.697426.

Tollefsen, Andreas Forø, Håvard Strand, and Halvard Buhaug. 2012. “Prio-Grid: A Unified Spatial Data Structure.” Journal of Peace Research 49 (2). SAGE Publications:363–74. https://doi.org/10.1177/0022343311431287.

Vicente-Serrano, Sergio M., Santiago Beguería, and Juan I. López-Moreno. 2010. “A Multiscalar Drought Index Sensitive to Global Warming: The Standardized Precipitation Evapotranspiration Index.” Journal of Climate 23 (7). American Meteorological Society:1696–1718. https://doi.org/10.1175/2009jcli2909.1.

World Resources Institute. 2014. “Rights to Resources: The Status of Local Natural Resource Rights in National Laws in Sub-Saharan Africa.” Washington, DC: World Resources Institute. https://datasets.wri.org/dataset/rights-to-resources-map.